1. Field of the Invention
The present invention relates to generally to air conditioning systems for vehicles and vehicles comprising such air conditioning systems. In particular, the present invention is directed towards air conditioning systems and vehicles, in which a sector gear is used to increase the stroke length of an air mixing damper of the air conditioning system, without increasing the size of the air conditioning system.
2. Description of Related Art
Referring to FIGS. 7-9, a known air conditioning system 70 for a vehicle (not shown), such as the air conditioning system described in EP1312494A1, includes a casing 71, and an air duct 72 including a first air path 75 and a second air path 76 formed within casing 71. Air conditioning system 70 also includes an evaporator 73 and a heater 74 positioned within air duct 72. Moreover, first air path 75 guides air which passes through evaporator 73 to heater 74, and a second air path 76 guides air which passes through evaporator 73 around heater 74. Air conditioning system 70 also includes a flexible, plate-type air mixing damper 77 positioned between evaporator 73 and heater 74 for adjusting the amount of air which flows within first air path 75 and the amount of air which flows within second air path 76.
Referring to FIG. 8, air mixing damper 77 includes a plurality of convex portions 78a, and plurality of concave portions 78b positioned between adjacent pairs of convex portions 78a. Air conditioning system 70 also includes a drive mechanism (not numbered). The drive mechanism includes plurality of first circular gears 79 which engage concave portions 78b and convex portions 78a. First circular gears 79 are mounted on a shaft 80, and an end portion 80a of shaft 80 projects outside casing 71. The drive mechanism also includes a second circular gear 81 mounted on end portion 80a, and a rack 82 or a third circular gear (not shown) connected to a wire (not shown). Rack 82 or the third circular gear engages second circular gear 81. Air conditioning system 70 also may include a plurality of damper guides 84, and air mixing damper 77 moves along damper guides 84.
Referring to FIG. 9, when a driver or a passenger of the vehicle moves a lever (not shown) for adjusting an interior temperature of the vehicle from a first position to a second position, rack 82 moves in a first direction along a base 83 via the wire. When rack 82 moves along base 83, second circular gear 81, shaft 80, and first circular gears 79 rotate, and air mixing damper 77 moves along damper guides 84. Referring again to FIG. 8, when air mixing damper 77 moves along damper guides 84, air mixing damper 77 adjusts the amount of air which flows within first air path 75 and the amount of air which flows within second air path 76. Because air mixing damper 77 is a plate-type air mixing damper, and the movement of air mixing damper 77 adjusts the amount of air which flows within first air path 75 and the amount of air which flows within second air path 76, air conditioning system 70 may be smaller than known air conditioning systems which use a rotary-type air mixing damper. Specifically, when a rotary-type air mixing damper is used, the size of the air duct is selected, such that the rotary-type air mixing damper rotates within the air duct without contacting the casing of the air conditioning system.
In air conditioning 70, the stroke length of rack 82 depends on the stroke length of the lever, e.g., increasing the stroke length of the lever increases the stroke length of rack 82, and the stroke length of air mixing damper 77 depends on the stroke length of rack 82, e.g., increasing the stroke length of rack 82 increases the stroke length of air mixing damper 77. A control panel of the vehicle includes the lever and a plurality of other components, e.g., a plurality of buttons for controlling a radio, a tape player, and a compact disc player; a plurality of buttons for selecting a mode for dispensing cooled or heated air into the interior of the vehicle; or the like. Consequently, the stroke length of the lever is limited by the size of the control panel and the amount of space occupied by these other components of the control panel. As such, it may be impractical to increase the stroke length of air mixing damper 77 by increasing the stroke length of the lever.
Decreasing the diameter of second circular gear 81 also increases the stroke length of air damper 77. Nevertheless, decreasing the diameter of second circular gear 81 also increases the amount of force needed to move the lever from the first position to the second position. Referring to FIG. 9, increasing a fulcrum distance A between the portions of second circular gear 81 which engage rack 82 and the rotational center of second circular gear 81 decreases the amount of force needed to moved the lever from the first position to the second position. Nevertheless, increasing fulcrum distance A also increases the diameter of second circular gear 81.
Therefore, a need has arisen for air conditioning systems which overcome these and other shortcomings of the related art. A technical advantage of the present invention is that the stroke length of the air mixing damper may be increased without increasing the size of the air condition system relative to the size of known air conditioning systems. Specifically, a sector gear is used to increase the stroke length of the air mixing damper.
According to an embodiment of the present invention, an air conditioning system for a vehicle comprises a first air path formed within an air duct, and a second air path formed within the air duct. The air conditioning system also comprises an air mixing damper for adjusting a first amount of air, which flows within the first air path, and a second amount of air, which flows within the second air path. The air mixing damper comprises a plurality of convex portions, and a plurality of concave portions, each of which concave portions is positioned between adjacent pairs of the plurality of convex portions. The air conditioning system also comprises a drive mechanism for driving the air mixing damper. The drive mechanism comprises at least one first gear engaging at least a portion of the plurality of convex portions and at least a portion of the plurality of concave portions. The drive mechanism also comprises a shaft coupled operationally to the at least one first gear, and at least one end of the shaft is positioned outside the air duct. Moreover, the drive mechanism comprises a second gear coupled operationally to the at least one end of the shaft, and a sector gear engaged with the second gear. For example, a gear ratio of the second gear to the sector gear may be at least 3:1.
According to another embodiment of the present invention, a vehicle comprises an air conditioning system. The air conditioning system comprises a first air path formed within an air duct, and a second air path formed within the air duct. The air conditioning system also comprises an air mixing damper for adjusting a first amount of air, which flows within the first air path, and a second amount of air, which flows within the second air path. The air mixing damper comprises a plurality of convex portions, and a plurality of concave portions, each of which concave portions is positioned between adjacent pairs of the plurality of convex portions. The air conditioning system also comprises a drive mechanism for driving the air mixing damper. The drive mechanism comprises at least one first gear engaging at least a portion of the plurality of convex portions and at least a portion of the plurality of concave portions. The drive mechanism also comprises a shaft coupled operationally to the at least one first gear, and at least one end of the shaft is positioned outside the air duct. Moreover, the drive mechanism comprises a second gear coupled operationally to the at least one end of the shaft, and a sector gear engaged with the second gear. For example, a gear ratio of the second gear to the sector gear may be at least 3.1.
Other objects, features, and advantages will be apparent to persons of ordinary skill in the art from the following detailed description of the invention and the accompanying drawings.